It is required that a knockdown container for shipping and storing articles be easily assembled and disassembled. Such a knockdown container mainly consists of a pallet as a base plate, a sleeve as a side frame, and a roof. A pallet has a sidewall connected to a bottom plate, and a sleeve stands on an inner side of the sidewall. A roof is placed over the sleeve making it a container for use.
An example of the above kind of container is a knockdown container described in Patent Document 1. The knockdown container consists of a pallet provided with a space on the lower side for inserting a fork of a forklift, sleeves axially connected to be foldable on each of the four sides of a bottom plate of the pallet, and a roof for closing an opening surrounded by the sleeves in a standing position. When the container is used, the sleeves are raised, the adjacent sleeves are fixed with a fixing member provided on the specific sleeve, and the roof is attached on an upper side thereof. When the container is not in use, the sleeves are folded down toward the inner side on which the canopy is attached to store the container.
Another example of a knockdown container is a container consisting of a pallet, a sleeve and a roof, which is assembled by fastening the pallet and the sleeve or the roof and the sleeve using a fastener. Such a knockdown container and a container fastener are known as described in Patent Documents 2 and 3.
The fastener described in Patent Document 2 comprises a clip pinching a lower edge of a sleeve and a substantially T-shaped locking rotary knob having a shank which is inserted into a knob housing cylinder provided on the clip. The clip is mounted on the sleeve, the sleeve is stood on an erected wall formed on the pallet, and a head portion of the locking rotary knob incorporated in the clip is pulled out through a lock hole on the erected wall to the outside of the erected wall of the pallet and rotated. Thus, the pallet and the sleeve are fastened, thereby assembling a knockdown container. With a protrusion formed on the inner surface of the knob housing cylinder on the clip, the rotation of the locking rotary knob is restricted.
The fastener described in Patent Document 3 is composed of a clip pinching a sleeve from both sides through a mounting hole formed on the sleeve and a substantially T-shaped key incorporated in the clip. The clip, while the key is incorporated therein, is mounted to the sleeve, a handle of the key is inserted into a connecting hole formed on the pallet, and the handle of the key which projects through the connecting hole is turned 90 degrees to lock the key to inhibit it from falling out from the connecting hole. Thus, the pallet and the sleeve are fastened, thereby assembling a knockdown container. The rotation of the key is restricted by a rib formed on the clip.    Patent Document 1: Unexamined Japanese Patent Publication No. 2002-114223    Patent Document 2: Unexamined Japanese Patent Publication No. H11-348986    Patent Document 3: U.S. Pat. No. 5,862,917